In general, a sleeping bag is a bag that is warmly lined or padded for sleeping outdoors, for example in a camper or a tent. Sleeping bags may also be used for sleeping on the floor inside a house, such as on a sleepover, or may be used as convenient bedding material when traveling.
Sleeping bags typically include a bottom portion, upon which an individual within the sleeping bag lays, and a top portion which extends over to cover the individual. Often, the top and bottom portions are made of a single, large rectangular insulated or padded fabric that is folded and attached along bottom and side edges to form the bag. The attachment is typically made by a zipper.
Sleeping bags are often folded and rolled into a tight ball for storage. After rolled, most rolled rectangular sleeping bags, are tied with tie cords, compression straps, or elastic straps, or may be otherwise secured so that the sleeping bag does not become unrolled during storage.
One problem associated with rolling of sleeping bags is that once the sleeping bag is folded (for example, lengthwise), it is often difficult to roll the sleeping bag without the edges of the sleeping bag being forced apart during the rolling process. For this reason, many users find it difficult to roll the sleeping bags into a tight, tidy configuration so that closure may be secured for transportation and storage.
Sleeping bags typically have a rough outer cover and a much softer, for example flannel, liner. The cover is made of more durable, rough material, so that it may resist wear, for example when the sleeping bag is laying on the ground or within a tent. The liner is typically made of a softer material, because the liner contacts the body of the user. One problem with such designs is that a user's head and arms often extend out of the sleeping bag and may come into contact with the coarse cover, which may be uncomfortable.